单选题
Which of the following are rational numbers?
A. -3
B.
C. 0
D.
E.
A. -3
B.
C. 0
D.
E.
【正确答案】
A、B、C、E
【答案解析】A rational number is one that can be written as a fraction of integers. The fraction 
is already written in this format. Similarly, 
, and 
. The numbers 
is already written in this format. Similarly, , and . The numbers